Influence of non-parabolicity on intravalley electron-phonon scattering; the case of bismuth

Abstract

The influence of the coupling between valence and conduction bands on the scattering of electrons by acoustic phonons is investigated for the case of bismuth. The calculation is based on a model employed previously for the lead chalcogenides and InSb. Elements of the weak field thermodynamic tensor have been analysed at low temperatures (T<80K) to give the energy dependence of the electron-phonon matrix element which is required in order to reproduce the experimental values. The dependence obtained implies that only the momentum plays a role, not the dispersion relations. For higher temperatures, the band structure of bismuth is known to vary, but the information is incomplete. Retention at high temperatures of the energy dependence of the matrix element found at low temperatures and with the requirement that the measured thermoelectric power be reproduced also leads to a change of the mass anisotropy with temperature.